倾斜Poiseuille-Rayleigh-Bénard流动的对流分区与动力学特性  

Convection partition and dynamics in inclined Poiseuille-Rayleigh-Bénard flow

作　　者：宁利中[1] 张珂 宁碧波[2] 刘爽 田伟利[3] Ning Li-Zhong;Zhang Ke;Ning Bi-Bo;Liu Shuang;Tian Wei-Li(Institute of Water Resources and Hydro-electric Engineering,Xi’an University of Technology,Xi’an 710048,China;College of Civil Engineering and Architecture,Jiaxing University,Jiaxing 314001,China;Department of Architecture,Shanghai University,Shanghai 200444,China)

机构地区：[1]西安理工大学水利水电学院,西安710048 [2]嘉兴学院建筑工程学院,嘉兴314001 [3]上海大学建筑系,上海200444

出　　处：《物理学报》2020年第12期68-76,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10872164);西北旱区生态水利国家重点实验室基金(批准号:2017ZZKT-2)资助的课题。

摘　　要：利用流体力学基本方程组的数值模拟,探讨了具有通过流动的倾斜腔体中普朗特数Pr=6.99的流体的对流分区与动力学特性.结果表明,对于相对瑞利数r=9,在通过流动雷诺数Re=1.5时,随着腔体倾斜角q的增加,系统出现均匀行波对流、非均匀行波对流以及单对流圈斑图;在通过流动雷诺数Re=12.5时,随着腔体倾斜角q的增加,系统出现局部行波对流、平行流及局部单对流圈斑图;进一步,对通过流动雷诺数Re和腔体倾斜角q的不同组合情况的数值模拟,发现在通过流动雷诺数Re和腔体倾斜角q构成的平面上,具有通过流动的倾斜腔体中的对流可以分成前述六种斑图区域,即均匀行波对流区、非均匀行波对流区、单对流圈区、局部行波对流区、平行流区及局部单对流圈区.研究了不同对流区域对流最大垂直流速wmax和努塞尔数Nu随着时间的变化特性.探讨了不同对流区域对流振幅A和努塞尔数Nu随着腔体倾斜角q变化的动力学特性.Since Henri Bénard first carried out experiments on convection in the fluid layer heated from below at the beginning of last century,and Lord Rayleigh first analyzed small disturbance theoretically,Rayleigh-Bénard convection has received much attention from many researchers,and has become one of the models to study the spatiotemporal structure,flow stability and dynamic characteristics of convection.The methods of studying the Rayleigh-Bénard convection are divided into experimental research,theoretical analysis and numerical simulation.With the development of computer,the research of numerical simulation has made great progress.Because the Rayleigh-Bénard convection can be accurately described by continuity equation,momentum equation and energy equation of hydrodynamics.Therefore,the numerical simulation based on hydrodynamics equations has aroused a lot of research interest.Based on the classical Rayleigh-Bénard convection,the influence of horizontal flow on the Rayleigh-Bénard convection can be studied by applying horizontal flow to one end of the horizontal cavity.On the other hand,the influence of cavity inclination on Rayleigh-Bénard convection can be studied by considering the variation of inclined angles in the cavity.Some valuable convective properties have been obtained.In order to reveal some new convection structures or phenomena,the effects of cavity inclination and through-flow on Rayleigh-Bénard convection are considered at the same time in this paper.By using the numerical simulation of the basic equations of hydrodynamics,the convection partition and dynamic characteristics of the fluid with Prandtl number Pr=6.99 in the inclined cavity with through-flows are discussed.The results show that for the reduced Rayleigh number r=9,the system presents uniform traveling wave convection,non-uniform traveling wave convection and single roll convection pattern at the through-flow Reynolds number Re=1.5 with the increase of the inclined angle q in the cavity,that for the through-flow Reynolds number

关 键 词：通过流动 倾斜腔体 对流斑图 分区 动力学特性 

分 类 号：O35[理学—流体力学] O175[理学—力学]